Method for recovering soluble matter from air currents in driers



Feb. 1 1927. 1,615,872

0. FABER METHOD FOR RECOVERING SOLUBLE MATTER FROM AIR CURRENTS INDRIERS Filed Feb. 6, 1922 2 Sheets-Shet 1 m vi/vra/e ATfOR/VEKQ Feb. 11927-. 1,615,872

0. FABER METHOD FOR RECOVEFRING SOLUBLE) MATTER FROM AIR CURREN TS INDRIERS Filed Feb. 6, 1922 2 Sheets-Sheet 2 Patented Feb. 1, 1927.

tlhiilfhlm STATES imam PATENT @FHQE.

OTTO FABER, 0F BUFFALO, NEVT YGBK, AEiSIGNGE. TO THE GEO. L. SQUIER(30., 015

BUFFALO, NEW YORK.

METHOD FOR. RECOVEBING SQL'UBLE MATTER FROM AIR CURRENTS IN DRIERS.

Application filed February This invention relates to methods forrecovering soluble matter from air currents discharged from driers, suchfor example as rotary drum driers. a

The invention is intended primarily for use in connection with rotarydrum driers of the kind which are commonly employed for drying sugar andother materials, and which include a revolving drum in which thematerial to be dried is acted upon by a current of heated air. This aircarries with it finely divided particles of the material which is beingdried and heretofore it has been customary to pass this air through adust separator to remove the greater part of the material from the air.vVhen the drier is used in connection with certain materials, such forexample as sugar, this dust laden air is explosive.

The objects of this invention are to provide an improved method ofrecovering the finely divided material from the air in such a mannerthat the recovered material can be readily converted into the desiredform; and also to improve methods of this kind in other respectshereinafter specified.

In the accompanying drawings:

Fig. 1 is a side elevation of a drum drier provided with means embodyingthe invention for recovering soluble matter from the air currents.

Fig. 2 is a f agmentary sectional plan view thereof on line 22, Fig. 3.

Fig. 3 is a fragmentary central sectional elevation thereof.

Fig. 4 is an end view thereof.

In. carrying out my improved method. 1 bring the dust-carrying air whichis discharged from the drier into intimate contact with a liquid. which.is adaptedto take from the air the particles of the material carriedthereby, and this liquid may be used repeatedly so that when the methodis used in connection with the drying of soluble material the liquidgradually becomes more concentrated, and after the desired concentrationor density has been reached, the liquid is evaporated to recover thematerial dissolved therein, fresh liquid. being introduced to replacethe liquid which hasreached the desired density. This method has theadvantage that it can be carried out in immediate proximity to the airdischarge end of the drier, so that the danger of explosion of thedust-carrying air is greatly reduced.

6, 1922. Serial No. 534,314.

Furthermore, by making a solution of the material carried by the air,this material can be readily recovered and is free from insolubleimpurities.

A represents the rotary drum of a drier, which may be supported onsuitable bearings a and rotated by any suitable mechanism. This drum isarranged at an inclination and receives the material to bedried at theupper end thereof through a spout a or the like, and discharges thedried material at the opposite end thereof, at which end warm air isadmitted which passes through the drum from the lower to the upper endthereof to remove moisture from the material which is being dried. Allof these parts have hereto-fore been used in connection with driers andof themselves constitute no part of this invention.

The material in passing through the drum is repeatedly subjected to theair currents passing through the drum so that the reels ture in thematerial. is gradually taken up by the air. Consequently, the materialbefore being discharged from the drum becomes very dry so that finelydivided particles of the material in the form of dust, are taken up bythe air and carried through the drum and out of the upper end thereof.in order to avoid loss of the n'iaterial which is being dried, theparticles of the material carried by the air must be removed therefromand 1y induces a flow of air through the drum A. The means for removingthe finely divided particles from the air current are arranged in thehousing B between. the end of the drum and the fan 0 and are prefer ablyin the form of a device for washing the air with water or other suitablefluid. Any suitable means may be provided for this purpose, such forexample as aseries of battles D which are preferably so arranged as toforn'l passages in which the direction of flow of the air is changed andagainst which the air impinges, and means are provided for wetting thesurfaces of the baiiies with water or other suitable liquid. In theconstruction shown, a series of flooding nozbaiiies is, broughtintointimate contact with V the wetted surfaces thereof in such a mannerthat the particles of material contained in the air are removedtherefrom and deposited on the wetted surfaces of the battles and aredissolved in the liquid. The air washing means described are preferablyemployed, Lut itis not intended to limit the invention to beusedinconnectiou with the particular air washing appliances shown since anyother means for removing the particles of material from the air by meansof liquid may be employed.

The circulating oi": the air washing liquid in the manner shown in, thedrawings so that the liquid may be used as many times as desired, hasthe advantage that the liquid may in this manner attain the. desireddensity. After the circulating liquidhas reached the desired density it.may be removed from the reservoir F in any suitable manner and may beevaporated to recover the soluble matter. In Fig. 1 an evaporating panor analogous ,device G is shown diagrammatically, a. two-way valve gbeing arranged inthe supply pipe 6 whichisadapted to connectthe pumpwith the supply pipe for directing the liquid to the baliles or with apipe for discharging the liquidto the evaporating pan.

The method described has the advantage of very efiiciently removing thesolid matter fromthe air, and the air washing apparatus occupiesverylittle space and can he placed directly into the housing B in closeproximity to the air dis 'harge end of the drum drier. T he airdischarged irointhc air washer is so free from dust and also suflicient-1y cooled by. contact with theliquid that it vcan be discharged direitlyinto the room in which the drier 1s loeatedytherebyelnnmatingthenecessity for air passages to conduct this air out of thebuilding. 'lncase the apwhich when suspended in finely divided form inthe air form an explosive mixture, the danger of explosion is verygreatly reduced in the first place, on account of the eoinparativelysmall volume of dust-laden air, due to the fact that the air washer isin close proximity to the air discharge drum of the drying drum, and inthe second place, because, the suction tan operates on the air after thesame has passed through the wash ing meansso thatany. sparks which mightbe p roducedby. the fan cannot cause-an explosion.

While in many cases it isdesirable to subject theliquid repeatedly tothe-air passi n. ;.out otthe drier, yet it is not intended to limit theinvention to such use,since in many installations, for example in sugarmills where much wateuis used during theaprocessof making, sugar theWater may be passed through theair washer only once, and then used insome partofthe process of manufacture, where the soluble materialv inthe water will be recovered.

I claim as, my. invention: 7

1.. .The hereindescribed method of recoversolublev solids, in finely comninuted torn] from air currents discharged from driers, consisting ofpassing the air, immediately upon. leaving a..,drier, into, intimatecontact successively with differentportions 0t liquid vto cause theliquid to takeparticles of ,said solids ,i' romthe air and formsolutions therewitlnwand .usingsaid solutionsin the ,inanutacture 0 f,Said, soluble solids.

2. The hereindescribedmethod of recovering soluble solids from aircurrents discharged i'rom. driers, consisting of passing he air,immediately upon leaving a drier, into contact .witlrliquidto cause theliquid. to take particles or said solids from the air, and usingthe'liquid containing the dissolved solid matter in the manufacture otsaidsoluble solids.

3. In the process of nianirtacturing sugar, the hereindescribed.,uiethod o't recovering sue'ar from air currents dischargedfrom a \1 drier used for drying wet sugar of c ctalline form, cens stingol passing the airin niediately upon leaving the drier into contact withapluralityot lihns of water to cause the water to take the particles oisugar from the air andto dissolve the same and utilizing the water withthe sugar dissolved therein inthe process of making sugar.

' OTTO FABER.

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